This is just my advice and personal opinion, and you can take it or not. Different stuff is gonna work for different people. But me, I'm dropping those portable car air compressors and swapping it for a bike pump.

The air compressors are more costly, and wear out easily. Some start overheating after filling a single tire 5psi and this causes them to break over time. Last time I used one I spent about an hour of my day just trying to fill all my tires 5psi each, due to how long I had to wait in-between to keep the thing from overheating.

I think people overestimate how difficult or time consuming it is to fill a tire with a bike pump, especially if you're using sturdier trail tires that aren't supposed to be filled super high anyways. I can manually fill one of my car tires 5psi just about as fast as the air compressor I have can (I'm pretty confident that I am actually faster, but I haven't timed it), without having to wait an hour for the compressor to stop trying to kill itself over doing it's job. No doubt the aforementioned hour-long endeavor would have been 15 minutes at the absolute most if I'd done it manually. It is only as difficult as it is to fill a bike tire to that same psi. Just takes more pumps obviously.

Unless you are physically disabled and unable to use a manual pump for extended periods, or I guess if you would just rather spend more money on a really good compressor that doesn't overheat after 2 minutes (which hey, fair enough if you can afford it) I would highly recommend just dropping them and using a bike pump if you don't already. Don't be fooled into thinking that you need everything to be fancy, expensive and electronic, and that your own abilities aren't good enough to rely on 🤙